This is an application for continuation of a training program in Oncology: The Molecular Basis of Cancer. The program faculty are composed of twenty-eight preceptors pursuing research in areas related to cancer. This distinguished faculty have trained more than 450 graduate students and postdoctoral fellows and form a highly interactive community of mentors in state-of-the-art research facilities. Program strengths are its diversity of experimental systems, technical capabilities and a combined approach of molecular, cellular and developmental biology. With the inauguration of the Lewis Sigler Institute at Princeton and the inclusion of faculty from the Institute for Advanced Studies, we have expanded our program to include significant training at the interface of biology and computation, so that students and postdoctoral fellows become immersed in computational methodology and conceptualization in the context of cancer biology. This additional training will empower the next generation of cancer biologists to effectively bring the new tools of genomics and genome-wide analysis to the service of cancer diagnosis and treatment. The strength of this multidisciplinary effort at Princeton has been recently recognized by its designation by NIH as one of only five Centers of Excellence in Computational Biology. At the same time, association with the Cancer Institute of New Jersey, a Comprehensive Cancer Center, as well as courses, symposia, conferences and research collaborations are used to enrich the clinical related aspects of the training. Trainees visit clinical facilities where cancer treatment occurs and meet clinical fellows, with whom they can exchange ideas on translational research efforts. In addition to the special effort to emphasize cancer as a disease, course work, seminar series, symposia and retreats are all used to provide a broad educational experience in diverse experimental systems. The ultimate goal is to train original, creative and productive biomedical scientists who will advance our understanding of cancer, its origin, treatment and elimination in a lifetime of research. The training record of this grant in the past bears out our success in this goal.